1. Field of the Invention
This invention relates to an arm-chair for a patient, particularly for odontological use.
2. Description of the Prior Art
At present there are many arm-chairs available for odontological use and those most known are essentially of two types. A first type has a symmetrical anatomic seat, or a padded seat, of a limited extension in order to accommodate the top portion of the patient's legs up to the knee; a patient would dispose himself at sitting position thereon. A second type of arm-chair, and that of most widespread use, has a couch or cot type of extended symmetrical seat, so as to completely accommodate the patient's legs: the back is movable between two positions, that is to say a supine position and a sitting position, and is not adjustable in height.
These types of arm-chairs having a back that cannot be adapted to the individual patient and a headrest with much restricted movements, almost always in only one direction, do not allow a rational work area and cause the operator to take uncorrect and detrimental positions.
In odontology the operating field is of small size and almost always located in a cavity accessible through a narrow aperture; thus, it requires that an operator is placed in front of it, taking an orthopedically correct sitting position. The structures of the present arm-chairs raise an obstacle against the operator's lower limbs; whereby it is difficult to reach the correct vision distance both for standard visus and use of myopia, hypermetropy, presbyopia or magnifying lenses. Difficulty further arises in effecting a correct clinical examination with the patient's bipupillary axis arranged in horizontal and parallel direction to the dentist's bipupillary axis; such a position is essential in order to obtain functional and aesthetic data, and is the only one valid for controlling the ratios between the dental arches by direct vision; it being known, for example, how distorted or altered are the articular relationships at supine position. Many operations in surgery, prosthesis and orthodontia are also impossible without forcing an operator to detrimental contortions, flexions and rotations.
Therefore, the aim of this invention was to provide an arm-chair, particularly for odontological use, which would allow a comfortable position to a patient, while enabling an operator to operate at an orthopedically correct and comfortable position.